Four Motor Direct Driving System Axle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electric vehicles face challenges with unsprung mass and handling due to the weight of in-wheel motors, which can affect ride quality and efficiency, and often require transmission or gearbox systems that add complexity.
Innovation Solution
A driving system with multiple electric motors connected directly to the vehicle's axles and wheels, controlled by a vehicle control unit that distributes power based on inputs from accelerator pedals, brake pedals, and steering wheels, eliminating the need for a transmission or gearbox and allowing for independent motor operation and differential transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If in-wheel motors are used to eliminate transmission systems, then device complexity is reduced, but unsprung mass increases which adversely affects ride and handling
Solution Approach 1:
The system segments the powertrain by using four independent electric motors, one for each wheel, eliminating the need for a centralized transmission system. This segmentation allows direct drive to each wheel while maintaining control over individual motor placement and weight distribution.
Solution Approach 2:
The patent replaces the mechanical transmission system with an electronically controlled motor system. Instead of using a gearbox and differential mechanisms, the system uses electronic control units to independently manage each motor's output, substituting mechanical complexity with electronic control.
2Volume of moving object
If in-wheel motors are placed directly in the wheel cavity, then compactness is improved, but unsprung mass increases which adversely affects ride and handling
Solution Approach 1:
The patent moves the motors from a two-dimensional in-wheel placement to a three-dimensional arrangement where motors are mounted on the vehicle chassis and connected to wheels via axles. This dimensional change allows motor weight to be supported by the sprung mass (chassis) rather than adding to unsprung mass (wheel assembly).
3Ease of operation
If traditional transmission systems are used, then power distribution control is improved, but device complexity increases
Solution Approach 1:
The system implements feedback control through electronic control units that monitor wheel speed, vehicle acceleration, and other parameters to dynamically adjust power distribution to each motor. This electronic feedback mechanism provides precise power control without requiring complex mechanical transmission components.
Solution Approach 2:
The patent introduces electronic control units as intermediaries between the power source and the wheels. These control units manage power distribution, torque vectoring, and coordination between motors, replacing the need for mechanical intermediaries like gearboxes and differentials.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces unsprung mass, improves ride and handling, and enables efficient power distribution to each wheel, allowing for differential wheel speeds during turns without the need for a mechanical gearbox.
Implementation Method 1
Inverters may receive the output signals of the vehicle control unit and modify the voltage before it enters the electric motors
Data Source
AI summary
A driving system for electric vehicles. The driving system may have two or more electric motors, each with voltage inputs, which are connected to the axles and tires of the vehicle. A variable input control may provide a signal that indicates its current operation position to a vehicle control unit. The vehicle control unit takes the information from the variable input control and determines how much power to send to each of the electric motors' voltage inputs.